NWS Awards Contract for ASOS All Weather Precipitation Accumulation Gauge

On September 25, 2001, the NWS selected a contractor to develop a gauge to more accurately measure frozen precipitation. C.C. Lynch & Associates of Pass Christian, MS, will develop an All Weather Precipitation Accumulation Gauge (AWPAG) which will be integrated into the Automated Surface Observing System (ASOS). Lynch will team with Ott of Germany to develop and eventually produce the AWPAG.

The contractor will provide modified Commercial Off The Shelf (COTS) gauges for testing this winter. The development and qualification effort should take about nine months, but Rick Ahlberg, ASOS Product Improvement Manager, said there may be opportunities to shorten the time length. Once the AWPAG is qualified, a limited production of gauges will be provided for a three-month Operational Acceptance Test. If all goes well, Ahlberg said, full-scale deployment at 314 NWS sponsored ASOS sites would begin by March 2003 and extend through June 2004.

Last winter, the NWS conducted a competitive evaluation at five test sites among COTS gauges made by three manufacturers. The evaluation in the areas of technical performance, management, and cost resulted in the selection and award of the contract to Lynch (click here for a photograph of one of the COTS gauges). During the evaluation process, Lynch/Ott demonstrated viable solutions to problems with existing gauge design.

The AWPAG will measure precipitation by weighing it, said Ahlberg. "One of the challenges to automated measurement and real-time reporting has been the capturing of representative amounts of all types of precipitation." Ahlberg said many gauges perform well during liquid-only precipitation (rain, etc.) in that they correctly measure what falls into them. The difficulty arises when freezing or frozen precipitation sticks to the gauge orifice. That precipitation reduces the diameter of the orifice, reducing the amount of precipitation falling in the gauge. Further, that stuck precipitation does not get measured in real time. Both of these effects cause under reporting. Heating the orifice to melt the frozen precipitation solves this problem, but too much heating causes losses by evaporation. The challenge is to apply the optimum amount of heat and apply it only when it is needed.

"Another challenge is dealing with evaporative losses between events in an environmentally responsible manner," Ahlberg said. Traditionally, a thin layer of oil in the gauge floats on top of the water, retarding evaporation. Disposing of contaminated oil presents logistical difficulties, so there is a requirement for no oil in the new AWPAG.

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Winter Outlook, New Wind Chill Index Subject of Upcoming News Conference

A NOAA news conference on October 18, 2001, will give the media highlights of what may be in store for the coming winter. Reporters will be asked to help educate the public about the new wind chill index in effect this winter. NWS field offices can link to a graphic depiction of the new index at http://www.nws.noaa.gov/om/windchill/index.shtml.

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The National Academy of Sciences Committee on Partnerships in Weather and Climate Services has added information and a feedback mechanism to its website. The committee's web site at http://www.nationalacademies.org/partnerships solicits comments from interested parties and provides copies of information and feedback that has been submitted. The National Weather Service's written response to the committee's questions is now available (click on the Read Community Input link). The site also lists a calendar of planned meetings and provides other information that the committee has gathered.

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Personal security is on our minds often these days, so take a few moments and visit the NOAA Office of Security's home page. In addition to the latest Security Alerts in effect at NOAA facilities, the site contains a wide range of information you may find useful. Follow the link to Safety Tips for information on such topics as identity theft, vehicle and office theft prevention, domestic and workplace violence, and even laptop computer security.

The URL for the NOAA Office of Security home page is http://www.security.noaa.gov.

For employees at NWS Headquarters, there's also an article on pedestrian safety, which includes the general Montgomery County Code "right of way" laws for using crosswalks (Montgomery County, MD, includes the SSMC campus). According to the article, of the more than 1,800 pedestrian injuries due to collisions with motor vehicles in the past five years in Montgomery County, MD, 95 per cent were due to pedestrian errors.

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Also on the Web...

The CFO's Headquarters Support Services Branch web team has posted the new NWS Correspondence Handbook to the Executive Affairs website. The document was posted as a PDF file and can be found at:

http://www.nws.noaa.gov/executive_affairs/

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